Of late, in this art, it is desired to provide a silver halide photographic material which permits rapid processing, and produces highly preservable picture images and shows high processing stability and is available at low cost, and, particularly, permits rapid processing.
Thus subjecting a silver halide photographic material to running treatment with an automatic developing machine installed at each developing shop is practiced, but as one means of improvement in service to users, there has been a call for making development and returning the material to the user within the very day on which the request for development is received and, further, even returning the developed material in several hours after the request has been made is desired; as a consequence, need for rapid processing has been all the more enhanced. Further, reduction in the treatment time will lead to improvement in productivity efficiency, thus enabling cost reduction, and to attain this, alacrity in developing rapid processing is urgent.
For attainment of rapid processing, approaches from two phases of photo graphic materials and processing solutions have been taken. With regard to color developing, use of a higher temperature, higher pH, higher concentration of color developing agent, etc., have been tried and, further, use of such additives as development accelerators are known.
Mentioned as the aforementioned development accelerators, 1-phenyl-3-pyrazolidone disclosed in British patent No. 811,185, N-methyl-p-aminophenol disclosed in U.S. Pat. No. 2,417,514 and N,N,N',N'-tetramethyl-p-phenylene diamine disclosed in Japanese patent OPI publication No. 15554/1975, etc. may be cited.
However, these methods can not achieve adequate rapidity and their effect is often accompanied by performance degradation such as greater fogging.
On the other hand, it is known that the configuration, size and composition of the silver halide grains of the silver halide emulsion used in photographic materials have a large bearing on the speed of development, etc.; particularly, the effect of halogen composition is large; especially notably high rate of development is known to be achieved by use of high chlorine content silver halide.
On the other hand, the formation of dye image using silver halide color photographic material is made usually by oxidation of aromatic primary amine color developing agent itself, as it reduces the silver halide grains in the exposed silver halide photographic material, and subsequent formation of dye by reaction of this oxidized product with the couplers contained beforehand in the silver halide color photographic material. And for the couplers, usually, a three layer couplers which form three dyes of yellow, magenta and cyan for making reproduction by way of subtractive color process.
The dye image obtained with silver halide color photographic material is sometimes preserved for a long period under exposure to light or long kept in a dark place under short exposure to light and it is known that a discoloring or fading of the dye image notably, depends on the states of its preservation. Generally, the discoloring or fading of the former is called light discoloring of fading or light fading and discoloring or fading of the latter is called dark discoloring or fading or dark fading. When the color photographic material is kept semipermanently on record, the degree of such light fading or dark fading has to be suppressed to be as small as possible.
Mentioned as basic properties required of couplers are that first, their solubility in high boiling organic solvents, etc., shall be large, that they shall not readily crystalize in silver halide emulsion, their dispersibility and dispersion stability in silver halide emulsions being high, that they shall enable achieving excellent photographic characteristics and that the dye picture images obtained with them shall be fast to light, heat, moisture, etc. Especially, with regard to cyan couplers, attainment of improvement in resistance to heat and moisture, dark fading property, has recently been taken up as an important theme.
Hereto generally used cyan couplers, for example, those disclosed in Japanese patent publication open to public inspection (hereinafter referred to as Japanese patent O.P.I. publication) Nos. 37425/1972, 10135, 25228, 112038, 117422 and 130441/1975 and U.S. Pat. Nos. 2369929, 2423730, 2434272, 2474293 and 2698794 are unsatisfactory, being poor either in light or dark fading, particularly, in the latter.
For this reason, various cyan couplers have been examined in an effort to achieve improvement in the dark fading. As a result, for example, 2,5-diacyl amino type cyan couplers which are disclosed in U.S. Pat. No. 2895826 and Japanese patent O.P.I. publication Nos. 112038/1975, 109630/1978 and 163537/1980 and phenol type cyan couplers having an alkyl group with 2 or more carbon atoms at the fifth position which are disclosed in U.S. Pat. Nos. 3772002 and 4443536 have been found out to be cyan couplers excellent in the dark fading.
Generally, processing of silver halide photographic high-sensitive material is continuously run, while replenishing the processing solutions at various developing shops such as photographic laboratories, etc. In this situation, it is impossible to maintain the compositions of the processing solutions constant between the initial period and the latter half period of running and change in the compositions of the processing solutions brings about fluctuations in the photographic characteristics, particularly, graduation variation. This problem is growing more serious with diminishing replenishment of processing solutions in recent years.
It has become clear that when a cyan coupler represented by the general formula [I] is used in a high chloride content silver halide layer, the photographic characteristics are greatly altered by change in the compositions of the processing solutions and variation of conditions, resulting in failure to obtain stable photographic performance, and thus the problem of low processing stability.
What is called processing stability means the degree of fluctuation in sensitometic characteristics of the photographic material relative to fluctuations in the compositions of the treating solutions, pH and temperature and the amounts of compounds other than the components of the processing solutions mixed into it.
Complete prevention of mixing of bleach fixer into developer, of all these events, is nearly impossible, even when the setting of strict replenishing rate, prevention of evaporation and elimination of eluate from the photographic material are implemented; particularly, in roller conveyor or automatic developing machine, the amount of bleaching-fixer mixed into the developer will notably vary with varying amounts treated and depending on the squeezing method and in actual practice, if the replenishing rate of the treating solution has dropped, its replenishment cycle rate will lower, resulting in further difference in the mixing-in rate.
Further, the color developer is held at a high pH, but under the influence of the amount of the solution replenished, oxidation by air, etc., during the continuous operation, fluctuation in pH of color developer is unavoidable.
Variations in photographic performances, in many cases, increase of fogging and graduation change, due to such mixing of bleach-fixer into color developer or fluctuation in pH pose large obstacles to attainment of stable and proper color and gradation reproduction.
Because of the extreme difficulty in preventing the mixing-in of bleach-fixer and the pH fluctuation themselves for reasons above-described, there is a call for development of silver halide photographic materials which give only small changes in photographic properties, even when the mixing-in of bleach-fixer or pH fluctuation occurs, that is, those excellent in the so-called BF (bleach-fixer) mixing-in resistance and pH fluctuation resistance.
With the silver halide color photosensitive materials, dye image is formed by subjecting them to the color developing-etc. after exposure, but with silver halide color photographic materials using high chloride content silver halide emulsion containing coupler which is suitable for rapid processing, the rate of formation of the oxidized product of the color developing agent is often rapider than the reaction of forming dye through the coupling reaction between the aforementioned oxidized product and the coupler. For this reason, the oxidized product of the developing agent exists in large amount; this causes oxidation of the latent image uncleus formed by exposure, thereby inducing bleaching of the latent image; the larger degree of this latent image bleaching seems to be cause for increasing processing fluctuation of the high silver chloride content photosensitive materials.
Particularly, the high chloride content silver halide provides high speed development, but is known to generally have low resistance to the latent image bleaching by the oxidized product of the developing agent which is formed in excess.